Talve gear for steam engines



(No Model.) 6 8heets-Sheet 1.

G. s. STRONG. VALVE GEAR FOR STEAM ENGINES.

No. 355,035. Patented Dec. 28, 1886.

N. PETERS. Phom-Lilhcgraphm, wasmn mu, D. c

(No Model.) 7 6 Sheets-Sheet 2.

G. S. STRONG.

VALVE E AE FOR STEAM ENGINES.

No. 355,035. Patented Dec. 28, 1886.

N. PETERS. Piiclo-Lithalnplwr, Wialingion. D. C.

(No Model.) 6 Sheets-Sheet 3.

G. S. STRONG.

I VALVE GEAR FOR STEAM ENGINES. No. 355,035. Patented Dec. 28, 1886.

# m A H Z/ so 20 N. PETERS, Fholo'Lilhogrnpher. Wauhlngluu. D. C.

(No Model.) 6 Sheets-Sheet 4.

G. S. STRONG.

VALVE GEAR FOR STEAM ENGINES.

(No Model.) v 5 s Sheets-Sheet 5.

' G. S. STRONG.

VALAVE GEAR FOR STEAM ENGINES. No. 355,035. Patented Dec. 28, 1886.

N versus. vhmumn mbm Walhlnglon. 0' c BSheets-Sheet e,

( No Model.)

G. S. STRONG. VALVE GEAR FOR STEAM ENGINES.

Pabte nwdl Dec- N PETERS. Phmum m mr. Wllhington. m;

UNITED STATES GEOEGE s. STRONG,

PATENT @EEicE.

OF NEW Y RK, N. Y.

VALVE-GEAR FOR STEAM-ENGINES.

SPECIPICATICN forming part'of Letters Patent No. 355,035, dated December28, 1886.

Application filed August 30, 1886. semi No. 212,154. x0 mo le.)

To all whom it may concern:

Be it known that I, GEORGE S. STRONG, a citizen of the United States,residing at New York, county of New York, and,State of New York, haveinvented certain new and useful Improvements in Valve-Gear forSteam-Engines, fully described and represented in the followingspecification and the accompanying drawings, forming a part of the same.

This invention relates to a valve-gear which is adapted to be used inconnection with either locomotive, stationary, or marine steam-engines,it being the object of the invention to provide a reversible valve-gearwhich is operated from a single eccentric and is without slidingfrictional surfaces, all the parts working from stationary centers.

It is also the object of the invention to provide a valvegear which isoperated from a single eccentric and imparts an independent motion tothe induction and exhaust valves, by which the point of cut-off can bechanged without changing the exhaust, and by which the compression canbe changed without chang ing the admission.

It is also the object of the invention to so organize and arrange thevalvegear of a locomotive that the movement of the valve or valves willnot be affected by the movement of the engine on its springs.

As a full understanding of the invention can be best imparted by anillustration and detailed descriptionof the organization and operationof the valve-gear embodying the invention, all preliminary explanationof the invention will be omitted and a detailed description given,reference being had to the accompanying drawings, in which a valve-gearconstructed according to the present invention is shown as applied to alocomotiveengine, only such parts of the invention being shown, however,as are necessary to illustrate the manner in which the valvegear isapplied.

In said drawings, Figure 1 is a side elevation of the valve-gear for oneside of the engine, the engine being provided wit-h separate inductionand exhaust valves. Fig. 2 is a plan view of the same. Fig. 3is across-section taken on the line was of Figs. 1 and 2, looking towardthe-left. Fig. 4 is a similar view taken 011 the line y y of the samefigures, looking toward the right.

Fig.,5 is a view similar to Fig. 2, illusit is to be understood that Arepresents the steam-cylinder, and a the connecting-rod, upon one sideof an ordinary locomotive, B the forward driving-wheel, and Z) itscrank-pin, upon the same side of the engine, and O the axle of theforward pair of driving-wheels.

D represents a portion of the framework,-

which rests upon the axles of the drivingwhecls and trucks and supportsthe boiler and other parts of the engine.

The val ve-gear for-only one side ofthe locomotive will be described, itbeing understood that the gear for the other side is the same.

The axle G is provided with the usual eccentric, 0, the strap 12 ofwhich is connectedto two forwardly-extending levers, 2O 21, the formerof which is rigidly connected to the strap 12, while thelatter ispivotally connected either to the strap, as shown at 11, or to the lever20. The levers 20 21 are bifurcated at their forward ends, and arefuloru med by being pivotally connected to thelower ends of a pair ofradius-rods, 18 19, which are pivotally connected at their upper ends toblocks 22 23, which are arranged to move freely on fixed segments 24:25. The blocks 22 23 are pivotally connected to rods 16 17, which rodsare pivotally connected at their opposite ends to arms 14 15, extendingfrom a rock-shaft, 27. The arm 15 is rigidly connected to the shaft 27,and the shaft extends transversely across the engine and is rigidlyconnected to the arm corresponding to the arm 15 on the opposite side ofthe engine. The arm 14: is not connected to the shaft 27, but is rigidlyconnected to a hollow shaft or sleeve, 26, which surrounds the shaft 27,and turns freely thereon, and also extends transversely across theengine, and is rigidly connected to the arm corresponding to the arm leton the opposite side of the engine. The arms 14 15, or the correspondingarms upon the opposite side of the engine, are

connected to rods 28 29, which are connected to levers located in thecab of the engine, so as to be under the control of the engineer. Bythis means the blocks 22 23 and thecorresponding blocks upon theopposite side of the engine can be moved along the segments, so as toregulate the movement of the induction and exhaust valves to reverse theengine and vary the point of cut-off, as will be hereinafter fullyexplained.

The short armsc of the levers 20 21 are pivotally connected at theirforward ends to rods 30 31, which are in turn pivotally connected toarms 32 33, extendingfrom a transverse rockshaft, 34. The arm 32 isrigidly connected to the shaft 34, while the arm 33 is rigidly connectedto a hollow shaft or sleeve, 35, which surrounds the shaft34 and turnsfreely thereon. The shaft 34 is provided with a second rigid arm, 36,which is pivotally connected to the rod 38, which operates theinduction-valves 40, v

the two valves being connected by a rod, 42, and the hollow shaft orsleeve 35 is also provided with a second rigid arm, 37, which ispivotally connected to the rod 39, which operates the exhaust-valves 41,these two valves being also connected by a rod, 43. The induction andexhaust valves 40 41 are of the gridiron-slide form shown and describedin my prior Letters Patent Nos. 320,892 and 320,894, and consequentlyrequire no detailed description.

The several parts of the valvegear just de scribed are supported asfollows: The shafts 34 35 are mounted in a long bearing, 49, which issupported on a light framework, (1, formed of a pair of plates, whichare secured to and extend forward from the axle-box roof the axle C. Theframe 12 is secured to the axle-box w by means of hooked portions 13,which hook over the rear side of the box, as shown in Fig.

1. The segment 24 is supported at its forward end on the inner end ofthe shaft 34 (seeFigs; 2 and 3) and at its rear end upon an upright rod,48, rising from thehollow shaft 26. The segment 25 is supported at itsforward end by being attached to the bearing 49 (see Fig. 2) and at itsrear end by being attached to a bracket, 47, rising from the frame d.(See Figs. 2, 3, and 4.) The shaft 26 is supported at one end in abearing, 46, secured to the inner one of the plates forming the frame d,(see Figs. 1, 3, and 4,) and at the other end in a similar bearingsecured to the inner one of the plates of the corresponding frame on theother side of the engine. i,

From the foregoing it will be seen that the valve-gear is supportedentirely upon the axlebox to, and is wholly independent ofthe mainframe-work D. This is a feature of impor tance, as by this means allparts of the valvegear are always maintained in the same position withrelation to the eccentric, so that the movements of the valves areregular and uniform, and are not affected by the movementof the engineupon its springs. This is not the case where the valve-gear is partly orwholly supported upon the main frame-work of the engine, because in suchcase the movement of the frame-work D with relation to theaxle O, andconsequently-with relation to the eccentric, caused by the compressionand expansion of the springs which are interposed between the axle andthe frame work, causes changes in the position of the valve-gear withrelation to the eccentric, which prevents the regular and uniformmovement of the valves. In order to give lateral support to the lightframe-work cl which supports the va1ve-gear, the main frame D isprovided with a vertical guide, 45, which extends upward between theplates forming the frame d, and moves freely up and down between them asthe position of the frame D varies. This guide, as will read il y beseen, affords a rigid lateral support to the frame d in whateverposition it takes with relation to the frame D. It may also in somecases be desirable to provide a yielding support for the forward end ofthe frame carrying the valve-gear. This can readily be done by means ofa spring, as 44, located between the plates forming the frame (I andinterposed be tween the frame D and a cap, 9, secured to the frame d, asshown.

Referring now particularly to the diagrams, Figs. 7 and 8, the operationof the valve-gear will be explained. In these diagrams the curved lineat represents the position of the segments 24 25,- the line Z representsthe valverods 38 39; the circle b indicates the travel of the crank-pinb; the circle 0 indicates the throw of the eccentric c,- the line aindicates the position of the connecting-rod a when the crank-pin is ateither its forward or rear dead center, which points are indicated onthe circle I) by the numbers 48 24, and the lines a a indicate thepositions of the connecting-rod when the crank-pin is at the limit ofits downward and upward movement, respectively, which points areindicated upon the circle I) by the numbers 12 36. The numbers 0 to 48at the right of Fig. 7 indicate the position of the cross-head pin whenthe crank-pin is at the various points in its travel indicated by thecorresponding numbers on the circle I). The position of the piston willof course always correspond-to that of the cross-head, but forconvenience only the crosshead will be referred to.

In describing the operation of the val vegear, it will first be assumedthat the blocks 22 23 are adjusted to the same position on theirrespective segments, and that that position is at the middle of thesegments, or what is termed midgear, as indicated atthe point z in Fig.7. With the blocks 22 23 in this position the lines it indicate thepositions of the eccentric levers 20 21, arms 32 33, and arms 36 37,when the crank-pin is at 48; the lines n indicate the positions of thesame parts when the crankpin is'at 24; the lines a indicate thepositions of the same parts when the crank-pin is at 12 and 36; thelinesoindicate the positions of the rods 18 19 and 30 31 when the crankpin is at 48 and 24; the lines o the positions of the same parts whenthe crank-pin is at 12, and the lines 0 the positions of the same partswhen the crank-pin is at 36.

Let it now be assumed that the cross-head pin is at 48 or 0-that is tosay, at the limit of its-forward stroke-and the crank-pin at its forwarddead-centerthat is to say, at the position indicated by 48 and 0 on thecircle I). As the eross'head moves rearward from 0 to 24, thereby makingits rearward stroke, the crank-pin will move from 0 to 24, therebymaking one-half of a revolution. During this time the eccentric 0 willmove the eccentric-1evers20 21 from the position indicated by'thelinento the positionindicated by the line a, and then on to the positionindicated by the line a. This will imparta compound movementtotheeccentric levers. consist in part of the longitudinal reciprocatingmovement due to the throw of the eccentric,whieh movement will, sincethe eccentriclevers are pivoted to the radius-rods 181.9 and to the rods30 31, cause said rods to move from the positions indicated by the lines0 to the positions indicated by the lines 0, and then back to thepositions indicated by the lines 0, thus causing the-ends of theeccentric-levers to move through arcs of circles the radii of which arethe rods 18 19 This movement of the eccentric-levers will not, however,owing to the position of the blocks 22 23, impart any movement to thevalves. In addition, however, to this longitudinal reciprocatingmovement the eccentric-levers will, owing to the change in theirposition from theline n to the linen, and then on to theline n he rockedupon their fulcra in the ends of the radius-rods 18 19,- so that theirforward ends will be vibrated in the arcs of circles the radii of whichare the arms '0 of thelevers. This compound movement of the levers willcause their ends, which are connected to the rods 30 31, instead ofmoving forward and back in the same path, to take the curved path oftravel indicated by the outline of the figure g from 48 to 12 and thenback to 24, and will, through the rods 30 31, rock the arms 32 33 and 3637 from the positions indicated by the lines a to the positionsindicated by the lines a, and then on to the positions indicated by thelines a and impart a corresponding movement to the valves.

From this it will be seen that the movement imparted to the valvesduring the stroke, as just described, is due entirelyto the rocking ofthe eccentric-levers upon their fulcra in the ends of the radius-rods 1819, and not to the longitudinal reciprocation of the levers. The extentof this movement, which is represented by the distance between thenumbers 48 and 24 on the figure g, is governed by the length of the arms1; of the eccentrio-levers, and relates only to the lap and lead of thevalves. When, therefore, the blocks 22 23 are in this position-t. 6.,midgear-the induction-ports are opened only to the extent of the lead ofthe valves. As the cross-head makes its return'stroke from 24 to 48, andthe crank- This compound movement will pin'moves from 24 to 48, therebycompleting the other half of its revolution, the operation justdescribed will be reversed, the eccentriclevers will move back from theline a to the line a, the radiusrods and the rods 30 31 will be vibratedfrom the lines 0 to the lines 0 andback, the ends of theeccentric-levers will the position assumed at the commencement of theoperation.

Let it now be assumed that the blocks 22 23 are shifted from the point zto the point :0, the crank-pin still continuing to move in the directionindicated by the arrow. When this is done, the positions of theradius-rods 18 19 will be changed, as indicated by the light dottedlines; and although the endsof the eccentric-levers will continue totravel in a path of the same form, as indicated by the outline of thefigure g, the position of' the path will be changed to that indicated bythe outline of the figure h, and the result will be that the ends of thearms 12 of the eccentric-levers as they travel from the point 48 to thepoint 12 and back to the point 24, instead of vibrating the arms 32 33and 36 37 from the lines 12 to the lines 1?, will vibrate these armsfromthe lines it to the lines a and back to the lines a and in travelingfrom the point 24 to the point 36 and back to the point 48 will vibratethe. arms 32 33 and 36 37 from the lines a to' the lines a and back tothe lines a, and give a corresponding movement to the valves. Themovement between thelines n and a" still represents the lap and lead ofthe valves, while the extended movement from n to 02* and from n to n-gives an additional movement to the valves, which opens them to agreater extent and keeps them open for a longer time. When the blocks 2223 are adjusted to the position indicated at x, as just assumed, thevalves will have their maximum throw, and this may be reduced to anydesired extent by adjusting the blocks from the point :0 toward theiroriginal mid-gear position.

Toreverse the engine it is only necessary to adjust the blocks 22 23 ina contrary directionthat is to say, to the other side of their IIOmid-gear positionfor instance, to the point 3 \Vhen this is done, theradius rods 18 19 will take the positionsindieated by the heavy dottedlines, and although the path traversed by the ends of the arms a of theeccentric-levers will remain the same in form, its position will beagain changed, so that it will now occupy the position indicated by theoutline of the figure It, and as a consequence the engine will bereversed.

In the explanation of the operation of the valve-gear which has thusbeen given it has been assumed, as before stated, that the blocks 22 23are adjusted to the same positions upon their segments. This will not,however, always be the ease, and, it! fact, it will usually happen thatthe blocks for the induction and exhaust valves will be adjusted todifferent positions, as it will frequently be desirable to change thethrow of the induction-valves with out changing the throw of theexhaustvalves, and vice versa. This, of course, can be readily done byshifting either one or the other of the blocks by means of the rods 2829. This eapability of adjusting the throw of the induetion and exhaustvalves independently of each other constitutes one of the importantfeatures of the invention.

The organization shown in Fig. 5 is the same as that already described,except that the rods and arms for operating the induction and exhaustvalves are located upon the inside instead of upon the outside of thesteam chests. This permits the shafts 3i 35 to be dispensed with, themotion of the rods 30 31 being in this case transmitted to thevalve-rods 38 39 by means of a pair of bell-crank levers,which aremounted to rock on a rod, 50, and the arms 32 33 and 36 37 of whichcorrespond to the arms 32 33 and 36 37 of the rock-shafts. This bringsthe whole valveoperating mechanism inside the line of the drivingwheels,as shown. In this organization, also, the rock-shafts 26 27 and arms 1415 are dispensed with, the blocks 2223 being connected directly to theoperating-rods 28 29, and the rear end of the segment 24 supported uponan extension of the same rod-which supports the rear end of the segment25. This organization will in many cases be found the most desirable.The operation is the same as already described.

It will also be readily understood that the valve-gear can be somodified, without radical change, as to be applied to those engines inwhich the induction and exhaust is controlled by the same valve.

A modified organization of the valve-gear for accomplishing thispurposeis illustrated in Fig. 6. I11 this case the induction and exhaustvalve is of the ordinary sliding form and is controlled by a rod, 38,connected to the arm 36, extending from the rock-shaft 34. The hollowshaft and arm 37 are of course omitted, as is'also the arm 33, rod 31,radiusrod 19, block and segment 23 25, rods 17 and 29, and theeccentric-lever 21, it being in such easenecessary to have but onesegment and block and one operating-rod for shifting the block, and thisbeing the case the rod 14 is connected rigidly to the shaft 27 and thehollow shaft 26 is omitted. In other respects the valve-gear is the sameas already described and has the same mode of operation.

It will of course be seen that the apparatus may be modifiedin otherrespects without departing from the invention. This is especially thecase in regard to the devices for adjusting the blocks 22 23 upon thesegments. The shafts 26 27, when used, need not be supported upon theframe (I, and these shafts therefore may be located in any otherconvenient posi- I that by means of the valve-gear herein described thevalve 01' valves is or are so moved as to secure a quick opening of theinductionport and a quick admission of the steam during the early partof the stroke ofthe-piston, which is a result which it is alwaysdesirable to attain. At the same time the exhaust is not closed untilthe piston has nearly completed its stroke and the crank-pin has nearlyarrived at its dead-center. This long-continued. opening of the exhaustis another result which it is also desirable to attain.

From the foregoing it will be seen that the valve-gear containing thepresent invention is easily and readily reversible and that a singleeccentric serves to operate it'in all positions, and, furthermore, that,when desired, the single eccentric can be made to operate independentinduction and exhaust valves, and that themovement of eitherthcinduction or exhaust "alves can be changed without changing the movementof the other.

Itwill also be seen that the whole valve gear is so supported that it isnot disturbed by the movements of the engine upon its springs, andconsequently all parts of the. apparatus always remain in their properposition with relation to the eccentric, thereby insuring a regular anduniform movement of the valve,

or valves.

\Vhat I claim is- 1. In a valve-gear for steam-engines, the combination,With a fixed segment and a block adjustable thereon, of a radius-rodpivoted-to said block, and the eccentric 0, having its eecentric-leverfulcrumed to said radius-rod and connected to the valve-rod,substantially as described.

2. in a valve-gear for steam-engines, the combination, with a fixedsegment and a block adjustable thereon, of a radius-rod pivoted to saidblock, the eccentric 0, having its eccentric-lever fulcrumed to saidradius-rod, and two rock-arms which are connected together and one ofwhich is connected to the eccentriclever and the other of which isconnected to the valve-rod, substantially as described.

3: In a valve-gear for steam-engines, the combination, with a singleeccentric and its eccentricstrap, of the two levers 2021, one of whichis rigidly secured to said eccentricstrap, and the other of which ispivoted to said strap or to the rigid lever, and both of which arefulcrumed so that each receives a compound motion, one part of saidmotion serving to cause the lap and lead of the valve, while ICS theother part effects the opening of the valve in addition to the lead,substantially as described.

4. In a valve-gear for steam-engines, the combination, with the twofixed segments having blocks'adjustable thereon, of the radiusrods 1819, pivoted to said blocks, the eccentrio 0, having the rigideccentric-lever 20, fulcrumed to one of said radius-rods, and thepivoted lever 21, fulcrumed to the other of said radius-rods, one ofsaid levers being connected to the induction valve or valves and theother to the exhaust valve or valves, substantially as described.

5. Ina valve-gear for steam-engines, the combination, with the two fixedsegments having blocks adjustable thereon, of the radiusrods 18 19,pivoted to said blocks, the eccentrio 0, having the rigideccentric-lever 20, fulcrurned to one of said radius-rods, and thepivoted lever 21, fulcrumed to the other of said radius-rods, rock-arms32 36, which are connected together and to one of said levers and theinduction valve or valves, and rockarms 33 37 which are connectedtogether and to the other of said levers and the exhaust axle-box of theengine, whereby the valvegear partakes of the motion of the axle-box andthe relation of its parts is not disturbed by the'movements of the mainparts of the engine, substantially as described.

7..In a valvegear for locomotive-engines, the combination, with the axleO, eccentric c, and axle-box w, of the frame d, mounted on the axle-boxand supporting the various parts of the valve-gear, substantially asdescribed. In testimony whereof I have hereunto set my hand in thepresence of two subscribing witnesses.

GEO. S. STRONG.

Witnessesz' J. A. HovEY, Ms. J. KENNEDY.

